The comments come more than a year after the company reorganized itself, splitting off its renewables and maintaining a fleet of almost 50,000 MW of fossil fuel generation.

Dive Insight:

That independent generators are under significant pressure from low prices in wholesale power markets is no longer news, but the NRG CEO put the situation particularly bluntly in his earnings call this week.

"I want to reiterate my belief that the competitive power sector is in a period of unprecedented disruption," Gutierrez told journalists and analysts. "I believe the IPP model is now obsolete and unable to create value over the long term."

A big part of the problem is in Texas, where the company has significant operations. Growing wind energy, lower gas prices and the decline of coal has helped turn the IPP model on its head.

The company's generation segment lost more han $500 million for the full year 2016, alongside renewables losses of more than $300 million. Only NRG's retail segment showed a profit (about $1 billion).

Gutierrez said that looking ahead, the company expects to continue to streamline the business, focusing on strengthening the balance sheet and delivering value to shareholders.

Adjusted EBITDA for the generation segment was $254 million lower than 2015, the company said. In its Gulf Coast region, a $93 million decline was due to lower average realized energy margins in Texas, due to a drop in power prices. Similarly, in its East Region NRG saw a $365 million EBITDA generation decrease from lower dispatch and capacity price.

Over at Bloomberg View, Liam Denning looks at how power markets in Texas wreaked havoc with NRG's strategy: While Texas energy demand has continued to climb, the state now gets more energy from wind farms than nuclear plants. And as fuel-free wind is dispatched first, it has driven down energy prices in recent years. Alongside declining natural gas and restrictions on coal, revenues for independent producers have dropped precipitously.

Correction: This post has been updated to remove a reference to the purchase of Oncor, a regulated utility in Texas. NextEra Energy, not NRG, is pursuing the acquisition.